1. Field of the Invention
The present invention relates to an elevator system and more particularly to an improvement in a governor apparatus for stopping an elevator system in case of emergency.
2. Description of the Prior Art
Hitherto, governors for elevator systems which in case of overspeed of the elevator cage act to detect the overspeed and grasp a governor wire rope have been installed at the upper part of the hoist way, but it is often the case in the building in which an elevator system is to be installed that a machine room for installing a governor cannot be provided directly above the elevator shaft, or, even if such a machine room can be provided, an entrance, opening, or the like to allow entrance into the room cannot be provided.
In order to remedy such difficulties, various countermeasures have been already proposed. For example, Japanese Utility Model Publication No. 37781/1972 (published on Nov. 15, 1972) proposes, as shown in FIG. 3, to install a governor at the lower portion of an elevator shaft, and Japanese Patent Publication No. 42763/1972 (published on Oct. 28, 1972) proposes, as shown in FIGS. 3, 5 and 12 thereof, installing a governor at the lower portion of the elevator shaft.
However, in those inventions, means for tensioning the governor wire rope are complicated, large in size, etc., and otherwise not fully satisfactory. That is, in the first invention mentioned above, as a tensioning device a number of elements are required such as a tension wheel, a weight, an L-shaped arm rotatably supported by a bracket, a lower guide wheel, etc., and also in the second invention mentioned above, a chain, a sprocket wheel with lock means, a weight, or a weight with lock means, etc. are required.